/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm/gm.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkBlendMode.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkFlattenable.h"
#include "include/core/SkFont.h"
#include "include/core/SkImageFilter.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRSXform.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkImageFilters.h"
#include "include/utils/SkTextUtils.h"
#include "src/core/SkImageFilter_Base.h"
#include "src/core/SkSpecialImage.h"
#include "src/utils/SkPatchUtils.h"
#include "tools/ToolUtils.h"
#include "tools/fonts/FontToolUtils.h"

#include <array>
#include <utility>

class SkReadBuffer;

static void draw_paint(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setImageFilter(std::move(imf));
    paint.setColor(SK_ColorGREEN);
    canvas->save();
    canvas->clipRect(r);
    canvas->drawPaint(paint);
    canvas->restore();
}

static void draw_line(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setColor(SK_ColorBLUE);
    paint.setImageFilter(imf);
    paint.setStrokeWidth(r.width()/10);
    canvas->drawLine(r.fLeft, r.fTop, r.fRight, r.fBottom, paint);
}

static void draw_rect(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setColor(SK_ColorYELLOW);
    paint.setImageFilter(imf);
    SkRect rr(r);
    rr.inset(r.width()/10, r.height()/10);
    canvas->drawRect(rr, paint);
}

static void draw_path(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setColor(SK_ColorMAGENTA);
    paint.setImageFilter(imf);
    paint.setAntiAlias(true);
    canvas->drawCircle(r.centerX(), r.centerY(), r.width()*2/5, paint);
}

static void draw_text(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setImageFilter(imf);
    paint.setColor(SK_ColorCYAN);
    SkFont font(ToolUtils::DefaultPortableTypeface(), r.height() / 2);
    SkTextUtils::DrawString(canvas, "Text", r.centerX(), r.centerY(), font, paint,
                            SkTextUtils::kCenter_Align);
}

static void draw_bitmap(SkCanvas* canvas, SkImage* i, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setImageFilter(std::move(imf));

    SkIRect bounds;
    r.roundOut(&bounds);

    SkBitmap bm;
    bm.allocN32Pixels(bounds.width(), bounds.height());
    bm.eraseColor(SK_ColorTRANSPARENT);
    SkCanvas c(bm);
    draw_path(&c, i, r, nullptr);

    canvas->drawImage(bm.asImage(), 0, 0, SkSamplingOptions(), &paint);
}

static void draw_patch(SkCanvas* canvas, SkImage*, const SkRect& r, sk_sp<SkImageFilter> imf) {
    SkPaint paint;
    paint.setImageFilter(std::move(imf));

    // The order of the colors and points is clockwise starting at upper-left corner.
    static constexpr SkPoint gCubics[SkPatchUtils::kNumCtrlPts] = {
        //top points
        {100,100},{150,50},{250,150},{300,100},
        //right points
        {250,150},{350,250},
        //bottom points
        {300,300},{250,250},{150,350},{100,300},
        //left points
        {50,250},{150,150}
    };

    static constexpr SkColor colors[SkPatchUtils::kNumCorners] = {
        SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
    };

    SkAutoCanvasRestore acr(canvas, /*doSave=*/true);
    canvas->translate(-r.fLeft, -r.fTop);
    canvas->scale(r.width() / 400.0, r.height() / 400.0);
    canvas->drawPatch(gCubics, colors, /*texCoords=*/nullptr, SkBlendMode::kDst, paint);
}

static void draw_atlas(SkCanvas* canvas, SkImage* atlas, const SkRect& r,
                       sk_sp<SkImageFilter> imf) {
    const SkScalar rad = SkDegreesToRadians(15.0f);
    SkRSXform xform = SkRSXform::Make(SkScalarCos(rad), SkScalarSin(rad), r.width() * 0.15f, 0);

    SkPaint paint;
    paint.setImageFilter(std::move(imf));
    paint.setAntiAlias(true);
    SkSamplingOptions sampling(SkCubicResampler::Mitchell());
    canvas->drawAtlas(atlas, {&xform, 1}, {&r, 1}, {}, SkBlendMode::kSrc,
                      sampling, /*cullRect=*/nullptr, &paint);
}

///////////////////////////////////////////////////////////////////////////////

class ImageFiltersBaseGM : public skiagm::GM {
public:
    ImageFiltersBaseGM () {}

protected:
    SkString getName() const override { return SkString("imagefiltersbase"); }

    SkISize getISize() override { return SkISize::Make(700, 500); }

    void draw_frame(SkCanvas* canvas, const SkRect& r) {
        SkPaint paint;
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setColor(SK_ColorRED);
        canvas->drawRect(r, paint);
    }

    void onDraw(SkCanvas* canvas) override {
        if (fAtlas == nullptr) {
            fAtlas = create_atlas_image(canvas);
        }

        auto drawProc =
                std::to_array<void (*)(SkCanvas*, SkImage*, const SkRect&, sk_sp<SkImageFilter>)>({
                        draw_paint,
                        draw_line,
                        draw_rect,
                        draw_path,
                        draw_text,
                        draw_bitmap,
                        draw_patch,
                        draw_atlas,
                });

        auto cf = SkColorFilters::Blend(SK_ColorRED, SkBlendMode::kSrcIn);
        auto filters = std::to_array<sk_sp<SkImageFilter>>({
                nullptr,
                SkImageFilters::Offset(0.f, 0.f, nullptr),  // "identity"
                SkImageFilters::Empty(),
                SkImageFilters::ColorFilter(std::move(cf), nullptr),
                // The strange 0.29 value tickles an edge case where crop rect calculates
                // a small border, but the blur really needs no border. This tickles
                // an msan uninitialized value bug.
                SkImageFilters::Blur(12.0f, 0.29f, nullptr),
                SkImageFilters::DropShadow(10.0f, 5.0f, 3.0f, 3.0f, SK_ColorBLUE, nullptr),
        });

        SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
        SkScalar MARGIN = SkIntToScalar(16);
        SkScalar DX = r.width() + MARGIN;
        SkScalar DY = r.height() + MARGIN;

        canvas->translate(MARGIN, MARGIN);
        for (size_t i = 0; i < std::size(drawProc); ++i) {
            canvas->save();
            for (size_t j = 0; j < std::size(filters); ++j) {
                drawProc[i](canvas, fAtlas.get(), r, filters[j]);

                draw_frame(canvas, r);
                canvas->translate(0, DY);
            }
            canvas->restore();
            canvas->translate(DX, 0);
        }
    }

private:
    static sk_sp<SkImage> create_atlas_image(SkCanvas* canvas) {
        static constexpr SkSize kSize = {64, 64};
        SkImageInfo atlasInfo = SkImageInfo::MakeN32Premul(kSize.fWidth, kSize.fHeight);
        sk_sp<SkSurface> atlasSurface(ToolUtils::makeSurface(canvas, atlasInfo));
        SkCanvas* atlasCanvas = atlasSurface->getCanvas();

        SkPaint atlasPaint;
        atlasPaint.setColor(SK_ColorGRAY);
        SkFont font(ToolUtils::DefaultPortableTypeface(), kSize.fHeight * 0.4f);
        SkTextUtils::DrawString(atlasCanvas, "Atlas", kSize.fWidth * 0.5f, kSize.fHeight * 0.5f,
                                font, atlasPaint, SkTextUtils::kCenter_Align);
        return atlasSurface->makeImageSnapshot();
    }

    sk_sp<SkImage> fAtlas;

    using INHERITED = GM;
};
DEF_GM( return new ImageFiltersBaseGM; )

///////////////////////////////////////////////////////////////////////////////

/*
 *  Want to test combos of filter and LCD text, to be sure we disable LCD in the presence of
 *  a filter.
 */
class ImageFiltersTextBaseGM : public skiagm::GM {
    SkString fSuffix;
public:
    ImageFiltersTextBaseGM(const char suffix[]) : fSuffix(suffix) {}

protected:
    SkString getName() const override {
        SkString name;
        name.printf("%s_%s", "textfilter", fSuffix.c_str());
        return name;
    }

    SkISize getISize() override { return SkISize::Make(512, 342); }

    void drawWaterfall(SkCanvas* canvas, const SkPaint& paint) {
        static const SkFont::Edging kEdgings[3] = {
            SkFont::Edging::kAlias,
            SkFont::Edging::kAntiAlias,
            SkFont::Edging::kSubpixelAntiAlias,
        };
        SkFont font(ToolUtils::DefaultPortableTypeface(), 30);

        SkAutoCanvasRestore acr(canvas, true);
        for (SkFont::Edging edging : kEdgings) {
            font.setEdging(edging);
            canvas->drawString("Hamburgefon", 0, 0, font, paint);
            canvas->translate(0, 40);
        }
    }

    virtual void installFilter(SkPaint* paint) = 0;

    void onDraw(SkCanvas* canvas) override {
        canvas->translate(20, 40);

        for (int doSaveLayer = 0; doSaveLayer <= 1; ++doSaveLayer) {
            SkAutoCanvasRestore acr(canvas, true);
            for (int useFilter = 0; useFilter <= 1; ++useFilter) {
                SkAutoCanvasRestore acr2(canvas, true);

                SkPaint paint;
                if (useFilter) {
                    this->installFilter(&paint);
                }
                if (doSaveLayer) {
                    canvas->saveLayer(nullptr, &paint);
                    paint.setImageFilter(nullptr);
                }
                this->drawWaterfall(canvas, paint);

                acr2.restore();
                canvas->translate(250, 0);
            }
            acr.restore();
            canvas->translate(0, 200);
        }
    }

private:
    using INHERITED = GM;
};

class ImageFiltersText_IF : public ImageFiltersTextBaseGM {
public:
    ImageFiltersText_IF() : ImageFiltersTextBaseGM("image") {}

    void installFilter(SkPaint* paint) override {
        paint->setImageFilter(SkImageFilters::Blur(1.5f, 1.5f, nullptr));
    }
};
DEF_GM( return new ImageFiltersText_IF; )

class ImageFiltersText_CF : public ImageFiltersTextBaseGM {
public:
    ImageFiltersText_CF() : ImageFiltersTextBaseGM("color") {}

    void installFilter(SkPaint* paint) override {
        paint->setColorFilter(SkColorFilters::Blend(SK_ColorBLUE, SkBlendMode::kSrcIn));
    }
};
DEF_GM( return new ImageFiltersText_CF; )